SXT Status Report 21 Oct. 1997 - 03 Nov. 1997 (Weeks 43-44) D. McKenzie, H. Hudson SUMMARY Solar activity increased over the last two weeks and at the time of writing the GOES background level had risen approximately to the B5 level. Alerts for M-class events have been coming thick and fast but... no events yet. There were no formal campaigns, although we did acquire some PFIs of the north polar region in an attempt to locate some jet activity. SOLAR ACTIVITY The background level increased to the B-level; five C-flares have occurred during the last two weeks. All but the last occurred during spacecraft nighttime, isn't that right? On 23-oct SXT witnessed the beginning of a CME, and images of the flaring loop region and coronal dimming were placed on the worldwide web at URL: ftp://isass0.solar.isas.ac.jp/pub/sxt_co/report_971024.html The active region AR8100 is providing numerous tiny flares, and may yet give us some M-flares. A C8 has just happened (04:40 UT 3-Nov). SXT INSTRUMENT STATUS AND CALIBRATION ACTIVITIES SXT continues to operate well. Three normal SXT errors (SEU's) occurred during week 43; all were recovered by KSC Tohbans. The CCD bakeout planned for week 43 was postponed until a time when KSC passes occur in local daytime (probably mid-November). The experiment to examine shutter-position influence on straylight has been stepped up; the dark frames which make up the sampling for this experiment have been moved into the Quiet/High FFI table to enhance the rate at which we acquire usable measurements. Data archiving is complete through Week 41, 1997. We have instituted a Web way of reporting status, which (ideally) will include a weekly "science nugget". The URL is currently of the form ftp://isass0.solar.isas.ac.jp/pub/sxt_co/report_971031.html, where the name will change as the weeks roll on (next 971110 most probably). Week 43 featured a CME, week 44 the EIT calibration rocket comparison. PASS CONFLICTS AT KSC Week 43: 6 KSC passes lost to other ISAS spacecraft. Week 44: 10 KSC passes lost to other ISAS spacecraft. CAMPAIGNS We carried out some views of the N polar region with a special 4x1 OR, at H. Hara's request. This and a KSC daytime active-region jet program (M. Shimojo) are targets of opportunity that we will introduce whenever it's feasible. For Yohkoh target planning, the SXT weekly observing plan is available on the Web at http://www.space.lockheed.com/SXT/html2/First_Light.html or with "finger campaign@isass0.solar.isas.ac.jp | more" . See http://sohowww.nascom.nasa.gov/operations/targets/today for SoHO target planning. VISITORS AND PERSONNEL Canfield arrived for a tour of tohban duty; a whole bunch of people went to Paris and some came back. Nitta returned to Japan. SEMINARS October 23: Slater led a discussion of the Rust review of "Helicity Conservation." This stimulated a lot more discussion, reading of papers, crude calculations, dim understanding, etc... - we were grateful for the timely visit of Canfield. October 30: Two seminars. First K. Shibasaki described observations made with the Nobeyama Radio Heliograph. The Nobeyama heliograph is capable of making full-sun images with 10-18 arcsec resolution. Shibasaki presented synoptic maps made with data from Nobeyama, SXT, and H-alpha, and compared the appearance of features seen in each. Next R. Canfield discussed the large flare of 15 November 1991. Canfield presented arguments that reconnection of a twisted loop with an untwisted loop may help to explain the observed (Doppler-shift) velocity fields. OTHER SCIENCE TOPICS The Oct. 16 EIT calibration rocket flew successfully, and the images are extremely nice. A rough first comparison with an SXT image can be seen on ftp://isass0.solar.isas.ac.jp/pub/sxt_co/report_971031.html. The rocket images are much cleaner and seem to have higher resolution - see the original 1024 on the Calroc Web page cited on that URL. As noted there, the comparison is an excellent example of matching gross features and missing every detail! TOHBANS Tohbans for Week 43: SSOC : Shimojo & McKenzie KSC : Yashiro & Shiozawa SXT_CO: D. McKenzie SXT_SW: G. Slater Tohbans for Week 44: SSOC : Shibasaki & Canfield KSC : Yashiro & Kasahara SXT_CO: D. McKenzie SXT_SW: G. Slater